Objective: To study the association between the polymorphism of human monoamine oxidase type A (MAO-A) gene and Parkinson's disease (PD). Methods: Fnu4H I restriction fragment length polymorphism (RFLP) and PCR-RFLP were used to detect the mutation of MAO-A gene. The frequencies of alleles and genotypes at the MAO-A Fnu4HI locus on the X chromosome in different PD group were compared with those of the control group. Results: It was found that the frequencies of G allele in the patients with PD and controls were 0. 613 and 0. 527 respectively, P = 0. 039; the frequencies of TT genotype were 0. 303 and 0. 415 (P = 0. 014), and the frequencies of GG genotype were 0. 564 and 0. 451 respectively (P = 0. 021). When the patients were divided into two groups by age-onset, significant difference in the allelic and genotypic frequencies was observed only between early-onset PD group and control group. And when the PD patients were grouped by sex, significant difference was observed only between male PD group and male control group (the frequencies of G allele being 0. 669 and 0. 500 respectively, P = 0. 005). Conclusion: This study revealed significant differences between PD group and control group in allelic and genotypic frequencies. The findings supported the hypothesis about an association between MAO-A gene and PD, suggesting that age at onset of PD and gender predisposition might be related to the putative association, and Fnu4HI SNP be a risk factor for PD.